Optimization of preparation parameters and parameters and resistivity of LiFePO₄ thin films by pulsed laser deposition Available to Purchase

Fe(III) iron phosphate was used as a precursor for preparation of LiFePO₄ (LFP) targets. Well-crystallized and homogeneous LiFePO₄ thin films were grown on nickel and Si substrates by pulsed laser deposition (PLD) in Ar atmosphere. Adjusting the deposition time enabled the growth of films with different thicknesses. when substrate temperature Ts was 600°C, resultant thin films grown on nickel foils were with comparatively pure olivine structure, while those thin film samples grown on Si were not well crystallized until Ts was increased to 700°C. In addition, compared with the theoretical resistivity of pure LFP, the resistivity of LFP thin films without any dopants grown on Si was decreased by 7 orders of magnitude based on results of four-point probe resistivity. Several approaches including X-ray diffractions, scanning electron micrographs, backscattered electron imaging, energy-dispersive X-ray analysis and wavelength dispersive spectroscopy were performed to characterize LiFePO₄ thin films, and possible impurities leading to high conductivity of LFP are iron-rich phases Fe(P₄O₁₁) and Fe₇(PO₄)₆.